Variability of amino acid digestibility of cereal grains in laying hens

83 Pages·2017·1.19 MB·English

by  T. Zuber

Institute of Animal Science
Department of Animal Nutrition
Prof. Dr. Markus Rodehutscord

Variability of amino acid digestibility
of cereal grains in laying hens

Dissertation
submitted in fulfillment of the regulations to acquire the degree
“Doktor der Agrarwissenschaften“
(Dr. sc. agr. /PhD in Agricultural Sciences)

to the
Faculty of Agricultural Science

presented by
Tobias Zuber
born in Heidelberg, Germany

2017
Die vorliegende Arbeit wurde am 10.11.2016 von der Fakultät Agrarwissenschaften der Universität
Hohenheim als „Dissertation zur Erlangung des Grades eines Doktors der Agrarwissenschaften“
angenommen.

Tag der mündlichen Prüfung: 07.12.2016
Dekan der Fakultät Agrarwissenschaften: Prof. Dr. Ralf T. Vögele
Leitung des Kolloquiums: Prof. Dr.-Ing. Stefan Böttinger
Berichterstatter, 1. Prüfer: Prof. Dr. Markus Rodehutscord
Berichterstatter: PD Dr. Holger Kluth
2. Prüfer: Prof. Dr. Dr. h.c. Rainer Mosenthin
3. Prüfer: apl. Prof. Dr. Michael A. Grashorn
This work was supported by funds of the Federal Ministry of Food, Agriculture, and
Consumer Protection (BMELV) based on a decision of the Parliament of the Federal Republic
of Germany via the Federal Office for Agriculture and Food (BLE) under the innovation
support programme.

TABLE OF CONTENTS

ABBREVIATIONS .................................................................................................................. III
LIST OF TABLES .................................................................................................................... V
LIST OF FIGURES ................................................................................................................. VII
1 General Introduction and Background ................................................................................ 1
2 Overview of Own Work ...................................................................................................... 5
3 General Discussion ............................................................................................................. 7
3.1 Possible sources of error .............................................................................................. 7
3.2 Factors affecting amino acid digestibility ................................................................... 8
3.2.1 Assay-based factors .............................................................................................. 8
3.2.2 Non-starch polysaccharides ................................................................................ 21
3.2.3 Protein fractions ................................................................................................. 27
3.3 Predictability of amino acid digestibility ................................................................... 28
3.4 Conclusions and perspectives for future research ..................................................... 29
References ................................................................................................................................ 33
4 Included Studies ................................................................................................................ 45
4.1 Manuscript I ............................................................................................................... 45
4.2 Manuscript II ............................................................................................................. 49
4.3 Manuscript III ............................................................................................................ 53
4.4 Manuscript IV ............................................................................................................ 57
5 Summary ........................................................................................................................... 61
6 Zusammenfassung ............................................................................................................. 65
I

ABBREVIATIONS

Beneath abbreviations for the units defined by the international system of units and the symbols
for chemical elements of the periodic table of elements the following abbreviations were used:

AA Amino acids
ADF Acid detergent fibre
Ala Alanine
Arg Arginine
Asp Aspartic acid
AX Arabinoxylans
BD Basal diet
β-glucan Mixed-linkage (1→3;1→4)-β-glucans
CP Crude protein
Cys Cysteine
DM Dry matter
Glu Glutamic acid
Gly Glycine
HDP Highly digestible protein
His Histidine
Ile Isoleucine
Leu Leucine
Lys Lysine
Met Methionine
NDF Neutral detergent fibre
NIRS Near infrared reflectance spectroscopy
NSP Non-starch polysaccharides
pc Prececal
Phe Phenylalanine
Pro Proline
SAS Statistical Analysis System
Ser Serine
Thr Threonine
Trp Tryptophan
Tyr Tyrosine
Val Valine

III

LIST OF TABLES

Table 1. Selected results and principle assay characteristics of studies examining the amino
acid digestibility of triticale and rye grain in poultry ............................................................... 10
Table 2. Selected results and principle assay characteristics of studies examining the amino
acid digestibility of corn grain in poultry ................................................................................. 11
Table 3. Selected results and principle assay characteristics of studies examining the amino
acid digestibility of wheat grain in poultry .............................................................................. 13
Table 4. Digestibility (%) of the four basal diets used in the digestibility trials with triticale,
rye, corn, and wheat ................................................................................................................. 19
Table 5. Concentrations of selected NSP fractions (mean and range, in g/kg DM, unless
otherwise stated) and respective coefficients of the variation of cereal grains grown under
standardized environmental and agronomic conditions ........................................................... 22

V